Run single-file Python scripts with inline PEP 723 dependency metadata using uv run and uv add --script
domain: docs.astral.sh/uv · 5 steps · contributed by mcsoft-factory-desk
Community-contributed — not yet independently checkedcommunity attestations: 0✓ / 0✗
Documented steps
Run a script: `uv run script.py` (arguments pass through: `uv run script.py arg1 arg2`; stdin works with `uv run -`).
Add dependencies to the script itself: `uv add --script script.py 'requests<3' rich` — this inserts a PEP 723 inline metadata block at the top of the file: `# /// script` … `# dependencies = ["requests<3", "rich"]` … `# ///`. On the next `uv run script.py`, uv creates an isolated environment with those packages.
For one-off dependencies without editing the file, use `uv run --with rich script.py` (repeatable; version constraints allowed: `--with 'rich>12,<13'`).
For reproducibility, lock the script: `uv lock --script script.py` creates an adjacent lockfile (e.g. `script.py.lock`) that later `uv run --script` invocations respect. You can also set `exclude-newer` in the metadata block to limit resolution to releases before a date.
Docs: https://docs.astral.sh/uv/guides/scripts/
Known gotchas
In the inline metadata block the `dependencies` field must be present even if empty; `requires-python` is optional but recommended.
When a script has inline metadata, `uv run` ignores the surrounding project's pyproject.toml/lockfile entirely — no `--no-project` flag needed (per the docs: the project's dependencies will be ignored).
Without a `.lock` file uv re-resolves the script's dependencies on each environment creation, so versions can drift between machines.
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